This invention generally relates to a method and device for determining real time within a vehicle. More particularly, this invention relates to a method and device for determining real time and temperature within a vehicle.
Many conventional electronic devices require a real time value including time and date. Current devices for keeping and determining the real time include a single relatively large microcontroller that utilizes a crystal oscillator for tracking the passage of time. The large microcontroller requires a relatively large amount of power and is susceptible to power interruptions and aging.
Further, the current devices for keeping track of time require a compensation factor due to temperature variations. The crystal oscillator vibrates or oscillates at a set frequency depending on material and cut. These oscillations vary with temperature and therefore require compensation to remain within a desired level of accuracy. Reduced variation due to temperatures can be obtained by using expensive high precision crystal oscillators. However, such high precision crystal oscillators require considerably more power as compared to a normal crystal oscillator. Many applications require a reduction in power usage to maximize battery life, therefore making the use of such high precision crystal oscillators impractical. The need for an accurate, low power, temperature compensated real time clock still exists.